In this May 21, 2021, members of South Korean K-pop band BTS pose for photographers ahead of a press conference to introduce their new single "Butter" in Seoul, South Korea. (Lee Jin-man / AP)

SEOUL — Jin, the oldest member of the K-pop band BTS, will begin his mandatory military service on Dec 13, South Korean newspaper Aju Business Daily reported on Thursday, citing unnamed military authorities.

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Jin, who turns 30 on Dec 4, will be deployed to a unit after receiving five weeks of training at the boot camp, the paper reported.

Spokespeople for BTS' agency, HYBE, and the South Korean Ministry of Defense declined to confirm the report.

All able-bodied men in South Korea between 18 and 28 must serve in the military for 18 to 21 months

In a social media post last week Jin hinted he was headed to a "front-line" position.

After years of uncertainty, the group announced in October it would go on mandatory military service, starting with Jin. The group plans to pursue individual projects and reunite in 2025 after all had served, HYBE said at the time.

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All able-bodied men in South Korea between 18 and 28 must serve in the military for 18 to 21 months. Some categories, however, have won exemptions, or served for shorter periods, including Olympics and Asian Games medal winners, and classical musicians and dancers who win top prizes at certain competitions. Some lawmakers had called for BTS to be exempted.

South Korea's defence minister has suggested BTS could still perform overseas while serving in the military.